Nahid Mahmoodimahpash; Bubak Souri
Introduction: Dust particles moved by air streams influence the quality of the environment. Chemical compounds of these particles are influential on the life’s quality of the residents of every region. Dust fall particles originated from the soil erosion has caused many problems for the residents ...
Introduction: Dust particles moved by air streams influence the quality of the environment. Chemical compounds of these particles are influential on the life’s quality of the residents of every region. Dust fall particles originated from the soil erosion has caused many problems for the residents of western Iran during recent years. Iran's geographical location in the vicinity of Iraq, Syria, and Saudi Arabia, where are major sources of dust, alongside issues such as climate change are among the roots for making and worsening this critical phenomenon. Hence, investigation and recognition of characteristics of this phenomenon including chemical characteristics of it may help the adaptation of pre-emptive measures and reaching scientific clues to control harms of this phenomenon. The main objective of this study was to compare the concentration of soluble ions in dust fall particles among various latitudes in western Iran. Material and methods: Simultaneous samplings were conducted monthly for one year in three cities i.e. Sanandaj, Khorramabad and Andimeshk using the passive method. The obtained data were then analyzed by Excel and SPSS v.23. For comparison of chemical characteristics of the dust fall particles, Coefficient of Divergence (CD) and Duncan's Multiple Range Test (MRT) were applied. Results and discussion: The results showed that calcium and sulfate with a concentration of 0.271 and 0.592 mg.g-1, respectively, had the highest concentration among the studied dust fall samples. High calcium concentration confirms that the dust fall on the three stations has natural origins, which are mainly calcareous soils and geological formations. Additionally, a high concentration of sulfate implies a share of evaporated sediments, particularly gypsum (hydrated calcium sulfate), among the studied dust fall particles. Calculation of CD also showed that chemical characteristics of dust falls in the three stations were mostly similar (CD < 0.5). Correlation of CD between cations in Sanandaj and Khorramabad and the wind factor (r= 0.99, p < 0.05), anions of Sanandaj and Andimeshk and rainfall (r= 1, p < 0.01) and moisture factors (r= 0.89, p < 0.05), respectively, demonstrated that the meteorological factors influence chemical characteristics of dust fall particles. MRT also showed that sodium as a highly soluble element had different concentrations throughout the three stations in the spring season (< 0.05). Moreover, compounds such as CaSO4, Ca(NO3)2, Mg(NO3)2, NaCl, KF and CaF2 were found in the three stations, which confirm the presence of gypsum, anhydrite, and halite among the dust fall particles. Conclusion: Environmental conditions in various latitudes influence the chemical characteristics of dust fall particles from various aspects. Nevertheless, values and changes in the concentration of soluble ions in the dust fall including Ca2+, Mg2+, Na+, and K+ cations and NO3-, SO42-, Cl-, and F- anions in the three stations of Sanandaj, Khorramabad, and Andimeshk were mainly similar. Hence, it can be concluded that the dust fall on the three studied cities originated from the same sources.